Using grep -E when greping conf files

The grep's \s notation, matching whitespace characters, is not
available when using basic regular expressions syntax since grep 2.15
(raised in f20), the default grep syntax. Although, It is available when using
extended regular expression, activated by the -E flag.

Change-Id: Ibf63316f4cec2ade80a6259a8ceb5b80f2537040
Signed-off-by: Yaniv Bronhaim <ybronhei@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/24829
Reviewed-by: Dan Kenigsberg <danken@redhat.com>